Thursday, October 14, 2010

Nami Nico Robin Anime

Pgp

var _gaq _gaq = _gaq.push (['_trackPageview']); (function () {var ga = document.createElement ('script'); ga.type = 'text / javascript'; ga.async = true; ga.src = (' https: '== document.location.protocol?' https: / / ssl ':' http://www ') +' .google-analytics.com/ga.js '; var s = document.getElementsByTagName (' script ') [0]; s.parentNode.insertBefore (ga, s); })();
The environment is full of toxins that can attack our cells. Cells have several strategies to defend against these substances. In some cases, using enzymes to convert the harmful molecules in order to make them harmless. In other cases sequester hazardous chemicals and expelling them in various ways. In other cases, such as we are going to analyze the cells can build specialized pumps to identify the harmful molecules and expel them outside the cell membrane.
The P-glycoprotein, shown here at the side and from the PDB 3g61, is the most common molecular pump that protects our cells from toxic molecules. It is inserted into the cell membrane and is continually looking for foreign hydrophobic molecules. When it finds one in the intrapulmonary a deep pocket in the protein and then changes its structural conformation. The new conformation of the protein causes an opening to the outside of cell and then release the harmful molecules beyond. Pgp to function needs an input of metabolic energy, and obtained by consuming one molecule of ATP to ensure that everything happens quickly.

course, to carry out its task, the P-glycoprotein should be able to expel many types of molecules. The researchers found that Pgp can pump out hundreds of different molecules with cell sizes ranging from a few tens of atoms up to hundreds of atoms. Most of these molecules are hydrophobic and are then dissolved in the cell membrane. Unfortunately, the Pgp not only expels the toxic molecules, in fact among the molecules that capture, there are also important drugs such as cyclosporine
and anticancer drugs. It follows that the activity of this protein from a certain point of view is dangerous because while on one hand provides protection to the cell expelling the harmful molecules reduces the effectiveness of other medications that we take in therapy.
block pump

Cancer cells found in tumors produced metastases, are more difficult to treat because they have become resistant to many drugs cancer. In some cases these cells have acquired a multidrug resistance by synthesizing a large amount of P-glycoprotein, which expels anti-cancer drugs continually sending them out of the cancer cell. Researchers are intensifying their efforts to find a way to block P-glycoprotein in cancer cells to make them more sensitive to chemotherapy.

Another approach is to look for drugs that enter in the active site of the protein and block the action inside.

Expor Structure
As you can see in the image on the side of P-glycoprotein consists of a long amino acid chain that folds in half very similar. In the figure the first half of the protein is colored blue, the second green. A short segment of protein that binds the two halves is not visible in this crystal structure (it is too mobile) and then is shown with a dotted line magenta. Notice how similar they are the two halves and how extensive their overlap. The researchers hypothesized that the protein has evolved as a result of an accidental duplication of the gene that coded, and this produced a protein consisting of two longer half nearly identical.

Sources:
pdb

Posted by admin at 5:17 AM

0 comments:

Post a Comment

Subscribe to: Post Comments (Atom)